The leak is definitely fake.
The more time goes on, the more it begins to mismatch what happened, so I will discard it. I apologize for posting it in the first place. Seriously, no more leaks for me!
As for Klonoa, don't put all of your eggs in the basket so soon. I think Klonoa has a surprisingly decent chance at becoming a Super Smash Bros. fighter. The game has had a history of reviving long-dead franchises, or bringing forth characters that enrich the formula of Smash with a refreshing moveset.
If we can have Banjo & Kazooie, Terry, and our first mild indie rep as a costume (Sans) it's really hard to predict who will make it next. At worst, fans of Klonoa will have to wait for the second Fighter's pass. And who knows, after that there may be a third!
What are your other picks for Smash Bros Fighters in the future? I would love to see Master Chief or Doom Slayer. They're like this game's Solid Snake or Bayonetta and I think they deserve it, just like Klonoa.